The use of so-called safety glazing or penetration resistant glazing for windows, windshields and the like utilizing polycarbonate resin layers as a structural component is well known. For example, glass polycarbonate resin laminates are described in U.S. Pat. No. 3,666,614, the glass and polycarbonate being cohered together using an ethylene-vinyl acetate copolymer. In U.S. Pat. No. 3,520,768, there are described laminates of relatively thick glass having a comparatively thin polycarbonate foil as the cohering material. It is also known to utilize certain polysiloxane-polycarbonate copolymers such as described in U.S. Pat. Nos. 3,832,419; 3,189,662; and 3,321,325 as the adhesive interlayers between a glass substrate and another substrate, such as a glass or a thermoplastic sheet, to provide for a reinforced laminate structure. Although the utility of such organosilicon-polycarbonate block copolymers provided for a variety of useful applications in the reinforced laminate area, one of the problems which developed was that the bond strength between the organosilicon-polycarbonate copolymer and the glass substrate was often insufficient for particular uses. Subsequently, primer compositions were developed to achieve improved bond strength between the glass substrate and the organosilicon-polycarbonate copolymer. One such primer composition, as described in U.S. Pat. No. 4,040,882, assigned to the same assignee as the present invention, was in the form of an aqueous-alcoholic reaction product of an aminoalkyl polyalkoxysilane and an alkyl carbonate.
While valuable results were achieved by the use of these primer compositions, the use of the two primer systems of the present invention provides laminates having greater bond strength between the glass substrate and the organosilicon-polycarbonate copolymer, especially under conditions of high moisture levels, than previously obtainable.